Low-energy excitations and transport functions of the one-dimensional Kondo insulator
Using variational matrix product states, we analyze the finite temperature behavior of a half-filled periodic Anderson model in one dimension, a prototypical model of a Kondo insulator. We present an extensive analysis of single-particle Green's functions, two-particle Green's functions, a...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SciPost
2023-06-01
|
| Series: | SciPost Physics |
| Online Access: | https://scipost.org/SciPostPhys.14.6.166 |
| _version_ | 1797798296070127616 |
|---|---|
| author | Robert Peters, Roman Rausch |
| author_facet | Robert Peters, Roman Rausch |
| author_sort | Robert Peters, Roman Rausch |
| collection | DOAJ |
| description | Using variational matrix product states, we analyze the finite temperature behavior of a half-filled periodic Anderson model in one dimension, a prototypical model of a Kondo insulator. We present an extensive analysis of single-particle Green's functions, two-particle Green's functions, and transport functions creating a broad picture of the low-temperature properties. We confirm the existence of energetically low-lying spin excitations in this model and study their energy-momentum dispersion and temperature dependence. We demonstrate that charge-charge correlations at the Fermi energy exhibit a different temperature dependence than spin-spin correlations. While energetically low-lying spin excitations emerge approximately at the Kondo temperature, which exponentially depends on the interaction strength, charge correlations vanish already at high temperatures. Furthermore, we analyze the charge and thermal conductivity at finite temperatures by calculating the time-dependent current-current correlation functions. While both charge and thermal conductivity can be fitted for all interaction strengths by gapped systems with a renormalized band gap, the gap in the system describing the thermal conductivity is generally smaller than the system describing the charge conductivity. Thus, two-particle correlations affect the charge and heat conductivities in a different way resulting in a temperature region where the charge conductivity of this one-dimensional Kondo insulator is already decreasing while the heat conductivity is still increasing. |
| first_indexed | 2024-03-13T04:01:26Z |
| format | Article |
| id | doaj.art-c4c514db4edf44e3bb11d0c3359a2706 |
| institution | Directory Open Access Journal |
| issn | 2542-4653 |
| language | English |
| last_indexed | 2024-03-13T04:01:26Z |
| publishDate | 2023-06-01 |
| publisher | SciPost |
| record_format | Article |
| series | SciPost Physics |
| spelling | doaj.art-c4c514db4edf44e3bb11d0c3359a27062023-06-21T13:25:48ZengSciPostSciPost Physics2542-46532023-06-0114616610.21468/SciPostPhys.14.6.166Low-energy excitations and transport functions of the one-dimensional Kondo insulatorRobert Peters, Roman RauschUsing variational matrix product states, we analyze the finite temperature behavior of a half-filled periodic Anderson model in one dimension, a prototypical model of a Kondo insulator. We present an extensive analysis of single-particle Green's functions, two-particle Green's functions, and transport functions creating a broad picture of the low-temperature properties. We confirm the existence of energetically low-lying spin excitations in this model and study their energy-momentum dispersion and temperature dependence. We demonstrate that charge-charge correlations at the Fermi energy exhibit a different temperature dependence than spin-spin correlations. While energetically low-lying spin excitations emerge approximately at the Kondo temperature, which exponentially depends on the interaction strength, charge correlations vanish already at high temperatures. Furthermore, we analyze the charge and thermal conductivity at finite temperatures by calculating the time-dependent current-current correlation functions. While both charge and thermal conductivity can be fitted for all interaction strengths by gapped systems with a renormalized band gap, the gap in the system describing the thermal conductivity is generally smaller than the system describing the charge conductivity. Thus, two-particle correlations affect the charge and heat conductivities in a different way resulting in a temperature region where the charge conductivity of this one-dimensional Kondo insulator is already decreasing while the heat conductivity is still increasing.https://scipost.org/SciPostPhys.14.6.166 |
| spellingShingle | Robert Peters, Roman Rausch Low-energy excitations and transport functions of the one-dimensional Kondo insulator SciPost Physics |
| title | Low-energy excitations and transport functions of the one-dimensional Kondo insulator |
| title_full | Low-energy excitations and transport functions of the one-dimensional Kondo insulator |
| title_fullStr | Low-energy excitations and transport functions of the one-dimensional Kondo insulator |
| title_full_unstemmed | Low-energy excitations and transport functions of the one-dimensional Kondo insulator |
| title_short | Low-energy excitations and transport functions of the one-dimensional Kondo insulator |
| title_sort | low energy excitations and transport functions of the one dimensional kondo insulator |
| url | https://scipost.org/SciPostPhys.14.6.166 |
| work_keys_str_mv | AT robertpetersromanrausch lowenergyexcitationsandtransportfunctionsoftheonedimensionalkondoinsulator |